Case for a watch



FIG. 1 is a top and side perspective view of a case for a watch, showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof; and,

FIG. 4 is a side elevational view thereof.

The structure shown in broken line is environmental only and does not form a part of the claimed design. 

The ornamental design for a case for a watch, as shown and described. 